Installation / Audio walk for the Mobile Audio Fest organized by Locus Sonus in Aix-en-Provence (France), november 2015.Mots croisés is a weaving of words of the city’s inhabitants and visitors to be discovered by scanning a series of QR Codes posted on the nine city centre’s advertising columns.In various places around the city center of Aix-en-Provence, unusual posters are visible on supports usually used for advertising. These posters show a very big QR Code on a white background. The intrigued passer-by, or the warned festival-goer, is invited to use their smartphone to scan the codes. Using earphones, they can then listen to a voice, to multiple voices, to streams of narratives or testimonies. These are about the city and start from a carefully chosen, sometimes unexpected, physical or social place somewhere in the immediate vicinity of the QR poster.Mots croisés questions the place, the promise and the function of signs in urban space and proposes a listening experience based on speech, on the multiple human words that write the (macro or micro) history of the places where we live. This project addresses the city as it is inhabited and invented from day to day by those who work, walk and live in it.